Heretofore, various compounds and catalysts have been used in the preparation of polyesters. One such particular polyester, as set forth in pending U.S. application Ser. No. 245,838, and currently being sold, achieved such a high clarity, neutral hue and low haze value that upon the normal reheat of a parison used in the blow molding of a polyester bottle, normal molding temperatures were not obtained during the usual residence time period in a light-emitting oven. That is, the polyester was of such high clarity that it did not sufficiently absorb the infrared light emitted by the oven. The present invention therefore relates to additives which absorb a sufficient amount of light and therefore improve the heat rate and yet maintain the high clarity, neutral hue and low haze value of the polyester.
U.S. Pat. No. 4,250,078 to McFarlane et al relates to thermoplastic polyester molding compositions containing iron oxides, which compositions exhibit reduced heat-up times and are useful as in the blow molding of beverage bottles. Moreover, this patent also discloses the utilization of certain anthraquinone dyes. This patent is not pertinent in that it does not relate to a high clarity, neutral hue or low haze resin or an article made therefrom having good reheat times, and does not suggest carbon black.
U.S. Pat. No. 3,951,905 to Sano et al relates to the incorporation of antimony-containing particles. It is stated that the polyester composition has excellent transparency and slipperiness. This patent is not pertinent in that it does not state that the polyester has low haze. Moreover, the patent does not relate to improved heat-up times and uses very high amounts of the antimony particles. Further, the class of particles is entirely different from that utilized by applicant.
The following patents and articles relate to various polyesters utilizing various compounds and catalysts therein but fail to teach or suggest the compounds utilized by applicant to make a high clarity, neutral hue and low haze polyester and articles made therefrom. These patents do not relate to any specific materials or to the use to improve the heat-up time of high clarity, low haze polyesters.
U.S. Pat. No. 3,795,639 to Chimura et al relates to a process for preparing linear polyesters utilizing a germanium compound, an antimony catalyst, and a phosphoric ester.
U.S. Pat. No. 3,732,182 to Chimura et al relates to a specific type of antimony compound used in the preparation of polyesters.
U.S. Pat. No. 3,965,071 to McClelland relates to polyesters wherein deactivation of a catalyst occurs through the reaction with a phosphoric acid or ester thereof.
U.S. Pat. No 3,842,043 to Chimura et al relates to a white, transparent polyester utilizing various catalysts such as germanium, along with various solubilizing agents.
U.S. Pat. No. 4,082,724 to Hewertson relates to preparation of polyesters utilizing high amounts of phosphorus, and also antimony to prevent colored degradation.
An article of Unitika Company, Plasdoc 31808 V/17 Dewent Publications, Apr. 1, 1974, relates to a polyester made by utilizing a specified type of phosphorus-containing compound.
U.S. Pat. Nos. 3,962,189 and 4,010,145 to Russin et al and 3,907,754 to Tershansy et al relate to catalyst inhibitor systems for preparing polyesters utilizing cataysts such as titanium, phosphates, manganese, cobalt, and the like.
U.S. Pat. No. 2,641,592 to Hofrichter relates to polyester preparation utilizing cobalt acetate and antimony as catalysts.
U.S. Pat. No. 3,028,366 to Engel et al relates to phosphate modifiers in association with antimony catalysts to produce colorless or white polyesters from dimethyl terephthalate.
Chem Abstract, Volume 93, 1980, No. 93:26877m "Effect of Phosphoric Acid on the Polycondensation of Bis(2-hydroxyethyl)terephthalate Catalyzed by Antimony III Compounds" relates to the production of higher molecular weight poly(ethylene terephthalate) obtained by utilizing the phosphoric acid.
As previously noted, none of these documents relate to an improved heat-up rate utilizing a specific type of material and yet maintain an exceptionally high clarity polyester having a low haze value.